Photoelectric switch for turning on lights in response to activating beam of light

ABSTRACT

Illumination system for store buildings, parking lots, and the like areas, activated for selected time intervals by a beam of radiant energy such as a light beam from a patrolman&#39;&#39;s flashlight, patrol car spotlight, etc. or condition sensors. A detector is mounted in or near the area to be illuminated, with the muzzle thereof aimed in such a way as to exclude inadvertent actuation by ambient light or reflected light, when actuated by a light beam or light beam pulses produces a gate signal for a solid state switch, such as a triac, which is in circuit with a source of alternating current power and a load circuit such as floodlights, and/or a low voltage lighting control system. A time delay device bypasses the solid state switch for a selected time interval, and after passage of the selected time interval, opens to deenergize the load circuit and conditions the circuit for subsequent actuation by a beam of radiant energy.

United States Patent [72] Inventor Harold Philip Nesbitt PrimaryExaminer-James W. Lawrence 9131 Hollyoak Drive, Bethesda, Md. 20034Assistant Examiner-Martin Abramson [2l] Appl. No. 793,442Attorney-Beveridge & DeGrandi [22] Filed Jan. 23, 1969 [45] PatentedJune 8, 1971 ABSTRACT: Illumination system for store buildings, parkinglots, and the like areas, activated for selected time intervals by [54]F a beam of radiant energy such as a light beam from a patrol- LIGHTman's flashlight, patrol car spotlight, etc. or condition sensors. 14 CM6 D win A detector is mounted in or near the area to be illuminated,

r g with the muzzle thereof aimed in such a way as to exclude in- [52]US. Cl. 250/214, advertent actuation by ambient light or reflectedlight, when 250/206, 317/130 actuated by a light beam or light beampulses produces a gate l Int. Cl H0 1 j 39/12 signal for a solid stateswitch, such as a triac, which is in circuit Field of Search 250/206,with a source of alternating current power and a load circuit 7/141 suchas floodlights, and/or a low voltage lighting control system. A timedelay device bypasses the solid state switch for [56] Referenm cued aselected time interval, and after passage of the selected time UNITEDSTATES PATENTS interval, opens to deenergize the load circuit andconditions 3,176,189 3/1965 Tabet 250/206 the circuit for Subsequentactuation y a beam of radiant ener- 3,2l0,6l l l0/l965 Krenke.. 250/206gym BIN 90 H 8| 82F Q ,82

I z 60 6l\ PATENTED Jun 8 I97] SHEET 1 [IF 2 HAROLD PHILIP NESBITT fATTORNEY/ PATENTEUJUN 8B7! 358422 SHEET 2 BF 2 INVENTOR HAROLD PMUPNESEH TT monmzvs PHOTOELECTRIC. SWITCH FOR TURNING ON LIGHTS IN RESPONSETO ACTIVATING BEAM OF LIGHT In the preferred arrangement, the outputpower to the load is by way of a normally nonenergized conveniencereceptacle on the detector housing so that auxiliary lighting units maybe used independently of the conventional lighting system. The

low voltage lighting control system includes a stepdown transformerplugged into the receptacle with low voltage wiring to a solenoid tocontrol a wall switch to turn on a conventional lighting system. Whenthe convenience receptacle is energized at the detector, the primarywinding of the transformer is energized via energization of thereceptacle to thus energize the low voltage secondary winding and supplyoperating power to. the solenoid to actuate a wall switch and turn thelights on and maintain the lights on as long as the solenoid isenergized. Deenergization of the receptacle and the subsequentdeenergization of the stepdown transformer and solenoid permits a springto return the solenoid arm to a normally inactivated position to turnoff the lights. Consult the specification for other features anddetails.

The present invention is directed generally to reliable illuminationapparatus designed as an aid to law enforcement officials or specialguards, as a deterrent to crimes, such as breaking and entering,burglary, etc., and more particularly to a remote lighting controlsystem activated by a beam of artificial radiant energy, such as aflashlight, spotlight or other light beam.

At the present time, shopping areas are inspected by foot or carpatrolmen, with the policeman or guard inspecting the darkened interiorby the slow process of peering through the door or display windows intothe darkened interiors or by attempting to illuminate the store interiorby means of a mu]- ticell flashlight or by patrol car spotlight. Ineither case, the glass of the store window or door tends to reflectsubstantial amounts of light back in the same manner as if the lightwere shined into a mirror,'-and the patrolman is at times at leastpartially blinded by the glare, and if there are intruders in the store,they may stand motionless or otherwise avoid being detected.

Objects of the present invention include the provision of a reliable,inexpensive radiant be'am actuated illumination system, an inexpensivelighting-control system in which regularly installed lighting systemsmay be turned on for selected time intervals by a patrolma'nsflashlight, scout car spotlight, etc. and which does not require expertinstallation or maintenance and an auxiliary lighting system forbuildings, parking lots etc. which is actuated for a selected timeinterval.

In its simplest terms, the present invention relates to an inexpensiveunobtrusive device that can be mounted inside a store display window, onthe exterior store front, or other appropriate location as desired,which, when struck by a strong beam of light activates an AC powersource, flooding the interior of the store with light for a selectedtime interval thus exposing to plain view anyone inside the premises. Anintrusion sensor or fire sensor may likewise activate the lightingsystem or an auxiliary lighting system to draw the attention of police,guards, etc.

A variety of methods of installation is available. Most commonapplication requires installation in the display window of a businessestablishment so as to be readily accessible to the light source of thepatrolman, watchman or police scout car. The light sensing. muzzle ofthe device should be pointed toward the outside and angled downwardly sothat a patrolman's flashlight or a scout car spotlight can activate thesystem, but at the same time, the muzzle must not be aimed so that itwill receive direct rays of sun or direct beams of automobileheadlights. An adjustable mounting bracket is provided to make itpossible for suspending from a wall, ceiling at a desired angle. Thebracket can be easily bent to achieve the desired position. Preferably,normally nonenergized female electrical convenience receptacles forplugging in spotlights 0 cles, a pair of terminals at the low voltagewinding of the stepdown transformer being available for low voltage,noncode, wiring to a solenoid mounted on a wall near a light switch. Thesolenoid has associated therewith a light switch actuating member which,in a nonactuated solenoid condition, is controlled so that in normaloperation, the light switch is off. Energization of the femalereceptacle having the stepdown transformer plugged therein energizes thesolenoid to turn on the light by on" translating movement of the lightswitch actuating member. Deenergization of the female receptacle after aselected time interval deenergizes the transformer and the solenoid andthe light switch actuating member is translated in a direction to turnoff the lights.

The above and other objects, advantages and features of the inventionwill become apparent from the following specification taken inconjunction with the accompanying drawings, wherein:

FIG. 1 is a perspective view of a preferred form of the apparatus with aportion of the detector housing removed to expose a portion of theinterior thereof,

FIG. 2 is a diagrammatic illustration of one installation of theinvention in a commercial building and a patrolmans flashlight beingused to actuate same, I

FIG. 3 is a circuit diagram incorporating one embodiment of theinvention;

FIG. 4 is a circuit diagram incorporating a further embodiment of theinvention;

FIG. 5 is a circuit diagram showing application of the invention toactuate conventional lighting systems;

FIG. 6 is a circuit diagram of a further embodiment of the invention.

With reference to FIG. 2 of the drawings, detector assembly 10 includesa housing 11 having welded or otherwise secured thereto mounting bracket12. Bracket 12 has a plurality of apertures 13 for nailing or otherwisesecuring to the ceiling or wall or other mounting surface. Other formsof mounting brackets and arrangements may be used. Bracket 12 isadjustable (by bending and/or twisting) to accommodate any desiredmuzzle angle as described later herein. Light beam limiting tube ormuzzle 14 which has blackened interior or bore 16 (tube 14 may benonreflecting black plastic tubing) has an end projecting outwardly fromwall 17 of housing 11. A light limiting cap 18 telescopes over the end14E of tube 14 projecting outwardly from the housing. The end 19 of cap18 has an aperture or hole 20 of a selected size to admit lighttherethrough into the bore 16 of tube 14. Tube 14 is of a length suchthat approximately 1 inch projects outwardly from the housing andapproximately 3 inches projects inwardly into the housing. Tube 14 ismounted in housing 11 by means of a grommet (not shown) in wall 17 orother mounting means. Photo detector 21 (shown by its symbol in FIG. 2)is positioned at the interior end 141 of light tube 14 so that a beam oflight directed at aperture 20 and generally along the axis of tube 14will strike photo detector 21, photo detector 21 being of the characterdescribed later herein. It will be appreciated that cap 18 is for thepurpose of limiting light entry to the bore 16 with the size of aperture20 being adjusted for different sensitivities. However, cap 18 may beeliminated and sensitivity adjustments made electrically as describedhereinafter. For a tube about 4 inches long and having a bore 16 ofabout three-eighths inch the size of hole 20 may be three-eighths inch,one-fourth inch thirteen sixty-fourths inch or one-eighth inch.

A power cord 22 having a grounded male plug 23 for plugging into anyconvenient outlet or female receptacle passes through grommet 24 intothe interior of detector hous ing 11 tosupply alternating current powerto the unit. A pair of conventional female receptacles 26 and 27 aremounted in the rear wall 28 of housing 11, such convenience outlets 26and 27 being in a normally nonenergized condition and energized by alight beam directed through aperture 20 along the axis tube 14 to photodetector 21. Various devices and control circuits may be energized uponenergization of either convenience outlet 26 of 27. For example, a floodlight 30, which may be a spotlight or conventional lamp having anextension cord 31 and ground male plug 32, is plugged into convenienceoutlet receptacle 27 so that upon energization of outlet 27 thespotlight 30 is turned or energized and upon deenergization of outlet 27spotlight 30 is likewise deenergized. A small stepdown transformer 40(FIG. (a bell transformer) may be contained within a small housing 35,which has extending therefrom male plug or prong elements 36A and 36Band a ground terminal 37, may be plugged directly into female receptacle26 to energize the primary winding of transformer 40, for purposesdescribed later herein, upon energization of female receptacle 26.Electrical circuitry may be mounted upon an insulating board 25 withinhousing 11 and a sensitivity adjustment knob 38 may likewise be mountedfor adjustment of the sensitivity of the device from the exteriorthereof. The ground wire in power cord 22 is connected directly to allelements shown as having a grounding means in a conventional manner toavoid electrical shock.

As shown in FIG. 1, the detector may be mounted upon a ceiling 39 withscrews (not shown) passing through apertures 13 in bracket 12. Floodlight 30 may be mounted at any convenient location in the store buildingwith power cord 31 (not shown in Fig. 1) being plugged into one of thereceptacles 26 or 27. Obviously, more than one flood light 30 may beplaced at various locations in the building or at areas to beilluminated, only one being shown for purposes of illustration. Again,with reference to FIG. 1, the muzzle of detector 10 is shown mounteddownwardly at an angle of about 45 so as to minimize inadvertenttriggering of the device by vehicle headlights, reflected light and/orambient sunlight. Also shown in FIG. 1 is a store front window 110 and apatrolman 's flashlight 111 being directed along the axis of tube 14 tophoto detector 21 within housing 11.

Figure 3 illustrates a preferred form of circuit incorporating theinvention. While silicon controlled rectiflers (SCR) may be used, triacsare preferred since these devices conduct in both directions whentriggered into conduction by a low energy positive or negative gatesignal with an attendant simplicity in overall circuitry. Once the gatesignal has be removed (e.g. the photo detector having a high impedancedue to no light beam thereon) the triac will continue to conduct. Inorder to turn off the triac, and condition the circuit for subsequenttriggering, the invention includes means for shunting or bypassing thetriac for the remainder of the triggered state of the circuit so currentconduction through the triac is only for a time sufficient to actuatethe timer circuit as described more fully hereinafter. The timer circuitincludes a series connected normally open contacts 71 and normallyclosed contacts 76 connected in shunt or bypass relation to the triac.Normally open contacts 71 are closed to complete the holding of a timedlatch or bypass of the triac. Thus, with reference to FIG. 3,alternating current power as supplied through conductors 22, fuse 60,and conductors 61 and 62 to load circuit 63 and terminals 64 and 66 oftriac 67. Gate electrode 68 of triac 67 is connected through sensitivitycontrol resistor 69 and photo detector 21 to terminal 66. Resistor 69may be adjusted by knob 38 so as to adjust the sensitivity of the deviceor, alternatively, resistor 69 may be fixed (about 200 ohms) and theopening in end cap 19 on tube 14 may be of varying sizes to adjust thesensitivity of the device to ambient conditions. A set of caps havingopenings 20 calibrated according to a range of sensitivities may beprovided.

A single convenience outlet receptacle is shown at 26 which correspondsto outlet 26 shown in FIG. 2, it being understood that more than oneoutlet may be connected as shown in FIG. 3. Timer relay'coil isconnected between input conductor 61 and terminal 64 of triac 6 7 and inparallel with relay coil 70 is a thermal time delay heater element 74.Relay coil 71 controls normally open contacts 71 whereas thermal timedelay heater elements 74 controls normally open contacts 76 beingconnected in a series circuit bypassing terminals 64 and 66 of I triac67 so that substantially no load current flows through triac 67.

This circuit operates as follows: A beam of light, indicated by arrow 78aimed along the axis of tube 14 (because of the length of tube 14 andthe size of opening 20 a few degrees off axis beams can trigger oractuate the detector, with dimensions given earlier herein definingincluded angles between about 6 to 13) passes through opening 20 andstrikes photo detector 21. Photo detector 21 may be a cadmium sulfidecell or other photo electric device and in the embodiment shown has anormally high resistance which is lowered upon being struck or impingedupon by a beam of light 78. The lowering of the resistance of photodetector 21 serves as a gate signal, through sensitivity resistor 69, ongate electrode 68 of triac 67 to turn on this triac 67 and cause currentto flow therethrough. Current flowing through triac 67'flows throughrelay coil 70 and energizes this relay to close contact 71. At the sametime, thermal time delay 74, which is in parallel with relay coil 70 islikewise energized and begins to heat up. It will be noted that onclosing of relay contact 71 the triac 67 is thus bypassed out of thecircuit and essentially returned to a normal nonconductive condition sothat the convenience outlet terminals 26 are now in an energizedcondition and effectively connected across the input conductors 61 and62 to the alternating current supply from power cord 22. With plug 32 inreceptacle 26, spotlight or floodlight 30 (FIG. 2) will be energized orturned on to illuminate the interior of a store building, for example,or other patrolled areas. The period of time for which the terminals ofconvenience outlet 26 are energized is determined by thermal time delayelement 74 and a period of time that it takes open normally closedcontact 76 to thereby be energized by terminals or receptacle 26. Thistime period may be of any selected duration but, for purposes ofspecificity is about two to three minutes. This time duration is amplefor the patrolman or guard to visually determine whether there is anyintruder within the premises or about the premises being patrolled.

Alternatively, or even simultaneously, instead of merely turning onfloodlight or spotlight 30, stepdown transformer 40 (FIG. 5), withinhousing 35 and plugged into one of the electrical outlet receptaclesshown in FIG. 2, has its primary winding 41 connected directly to prongs36A and 368 which are received in female receptacle 27, for example.Secondary winding 42 of transformer 40 has its ends connected to a pairof terminals 43 and 44 to which may be connected low voltage wiring 46which may be run in a noncode manner to the proximity of a light switch47 mounted on a wall of the premises being patrolled. Bifurcated switchactuating arm or member 48 is fitted over toggle lever 49 of switch 47and constrained by guides 58G to translate or move in an up and downdirection so that translatory movement of arm 48 upwardly serves to movetoggle 49 up and turn on the conventional store lights. This upwardmovement of arm 48 is effected by solenoid 50 which receives itsoperating current via low voltage wiring 46 from the secondary winding42 of transformer 40. In the embodiment illustrated, tension spring 52is connected to arm 48 to bias or maintain same at a down or offcondition so that any time that solenoid 50 is not energized toggleswitch lever 49 is down or off. It will be appreciated that push buttontype wall switches and the like may be actuated by equivalent apparatus,the only essential being that whenever solenoid 50 is deenergized, wallswitch 47 is maintained or biased to an off position. Hence, theoperation of the circuit described in FIG. 5, taken in conjunction withthe circuit of FIG. 3 with prongs 36A and 36B plugged in electricalreceptacle 26, is as follows: A beam of light 78 aimed at and enteringmuzzle aperture 20 strikes photocell 21 to lower the impedance thereofthereby serving as a gate signal to gate electrode 68 of triac 67through resistor 69. Such a gate signal switches triac 67 on to therebyenergize convenience receptacles 26 and 27 and, at the same time, relay70 and thermal time delay element 74. Contacts 71 are closed toestablish a latching or holding circuit about triac 67 to thereby permitsame to recondition or reset for subsequent operation. Energization ofconvenience receptacle 26 energizes the primary winding 41 oftransformer 40 to produce a stepped down low voltage on the secondarywinding 42 (l v. AC to 24v. AC is satisfactory). When transformersecondary 42 is energized, the low voltage wiring 46, as connected toterminals 43 and 44, is likewise energized to thereby energize solenoid50. Solenoid 50 is mechanically linked to arm 48 and hence onenergization of solenoid coil 50 the bifurcated arm is moved or shiftedupwardly in guides 48G thereby tensioning or stretching tension spring52 and moving toggle switch lever 49 upwardly to turn on theconventional lighting in a building or the premises being patrolled.Meanwhile, thermal time delay element 74 has been energized and isheating and, according to the time delay thereof, will open contacts 76to thereby open or deenergize the convenience outlets 26 and 27. Upondeenergization of convenience outlets 26 and 27, primary winding 41 oftransformer 40 is deenergized resulting in deenergization of thesecondary winding 42 and the attendant deenergization of solenoid 50.This permits spring 52 to return arm 48 downwardly to a nonenergized orunactuated condition to thereby move toggle switch lever 49 downwardlyand thereby turn off the lights.

In Order to permit normal use of light switch 47, the unit may bedetachably or pivotally mounted on the wall (not shown) adjacent switch47. Alternatively, bifurcated arm 48 may be shifted to the right todisengage the bifurcations from toggle lever 49, slots 485 being formedin arm 48 to permit this disengaging movement.

Preferable to using a thermal time delay is timer motor 80 as shown inFIG. 4 which circuit, except for timer motor 80 is essentially the sameas FIG. 3. On energization of timer motor 80, a cam 81 driven by timermotor 80 controls normally open contacts 82 (which in FIG. 4 are shownclosed or actuated) closed to affect the bypassing of triac 67. In thisembodiment, the rate of rotation of timer motor 80 and the diameter ofcam 81 determine the time period that the circuit remains triggered.There may be more than onenotch 81N so that cam 81 need not rotate afull revolution for each time interval. Normally, contact follower 82Fis in cam notch 81N so that the full voltage applied to the circuitthrough conductors 22 appear across triac 67 and no current flows to theoutput circuit constituted by the timer motor 80 and any load pluggedinto convenience outlet 26. When a beam of light is directed ontophotocell 21 through tube 14, the impedance or resistance of photocell21 is lowered to constitute a gate signal on gate electrode 68 of triac67 which triggers or switches triac 67 to a conductive condition.Current now flows through the triac and timer motor 80. As soon as timermotor 80 begins to operate and cam 81 is rotated, cam follower 82F movesout of the notch 81N to close contacts 82 to thereby form a bypass orparallel path to triac 67 and energize convenience 26. A load such asfloodlights 30 (FIG. 2) plugged in such convenience receptacle and/ortransformer 35 plugged into convenience receptacle 27 (FIG. 2) isenergized. As soon as motor 80 completes one revolution or the presettime interval, cam follower 82F drops into notch 81N to thereby opencontacts 82 and the circuit is ready for further triggering by a lightbeam directed upon photocell 21. A small pilot lamp 90 may be connectedacross the output terminals and used to adjust sensitivity of the deviceby adjustments of resistor 69 and to further indicate proper operationof the circuit.

As shown in FIG. 4, other sources of gate signals for triac 67 may beincorporated into the system. Thus connected in parallel with photocell21 shown a temperature sensor such as thermistor 121 which has a highresistance value corresponding to a normal ambient temperature and whichlowers its resistance significantly on an increase in ambienttemperature to produce a gate signal for triac 67. Additional conditionsensors may likewise trigger the circuit to turn on lights andilluminate the premises. For example, a humidity sensor 132 may closeswitch 131 to illuminate the premises on an abnormal increase inhumidity, or a sound sensor 142 may close switch 141 to illuminate thepremises on changes in noise level within the premises. In these lattercircumstances, as long as the abnormal condition persists the lightswill remain on or energized since after the end of the time interval oftimer cam 81 triac 67 will be retriggered as soon as contacts 82 open.This retriggering of triac 67 is effective to continue the running oftimer motor 81 and reclose contacts 82 so that the bulk of the loadcurrent flows through the bypass circuit for triac 67.

Figure 6 illustrates a modification of the invention which does notrequire the use of a semiconductor such as the triac illustrated inFIGS. 3 and 4. In this embodiment cadmium sulfide photocell 21' isconnected in series with relay coil and across input power conductors61' and 62'. Relay coil 170 controls a pair of normally open contacts171 and 172. Normally open contacts 171 are connected in parallel orbypassing relation to photocell 21 by means of conductors 173 and 174and serve as latching contacts for relay coil 170. Normally opencontacts 172 provide a circuit path to convenience receptacle 26 so thatenergization of relay coil 170 is effective to energize receptacle 26'.Thermal time delay resistance element 176 is connected in parallel withconvenience receptacle 26' and is energized therewith to controlnormally closed contacts 177 connected between input power conductor 62'and the lower end of relay coil 170.

With alternating current power on input conductors 61' and 62', thecircuit of FIG. 5 operates as follows: In the quiescent state, theresistance of photocell 21' is high so that only a very small currentflows through relay coil 170, such current being insufficient to actuateor energize the relay. When a beam of light or other radiant energyimpinges on photocell 21', the resistance thereof drops to permitsufficient current to flow through relay coil 170 to actuate normallyopen relay contacts 171 and 172 to a closed condition. Closing ofcontacts 171 provides a bypass for photocell 21 and connects relay coil170 directly to the input power conductors. Simultaneously with theclosing of contacts 171, contacts 172 close to connect convenienceoutlet 26' directly across input power conductors 61' and 62' to therebyenergize same and any load connected thereto. Thermal time delay element176 is likewise energized and begins to heat up associated normallyclosed bimetallic switch contact elements 177. After a selected timeinterval, contacts 177 open to deenergize relay 170 and recondition thecircuit for further operation. It will be noted that in thismodification, as well as the modification illustrated in FIG. 3,residual heat in the thermal time delay elements can affect the timedelay so that for repeated cycling or triggering, the time delay mayvary. For this reason the embodiment illustrated in FIG. 4 is preferredwhere it is desired to avoid slight variation in the time delay intervalon two triggerings of the circuit that are relatively close in time.

It is obvious that various changes may be made in the form andconstruction of the invention without departing from the spirit thereof.Hence, the invention includes such modifications and departures which asmay properly come within the scope of the claims appended hereto.

What I claim is:

l. Radiant beam controlled illumination apparatus comprising incombination,

a pair of alternating current power input terminals,

a pair of alternating current power output terminals,

conductor means directly connecting one of said input power terminals toone of said output power terminals,

radiant beam controlled switch means for directly electricallyconnecting the other of said input power terminals to the other of saidoutput power terminals for a selected time interval, said radiant beamcontrolled switch means including an electronic switch having a pair ofmain terminals and a gate terminal,

means connecting one of said main terminals to the said other of saidinput power terminals and the other of its main terminals to the saidother output power terminal,

radiant beam sensor connected between said gate terminal and said theother of said input power terminals, said radiant beam sensor applying asignal to said gate terminal upon impingement thereon of a beam ofradiant energy to render said electronic switch conductive between saidmain terminals,

timer means,

means connecting said timer means across said pair of output powerterminals,

normally open switch means closed upon energization of said timer meansfor a selected time interval,

means connecting said normally open switch means in parallel to the saidmain terminals of said electronic switch to thereby bypass saidelectronic switch for said selected time interval, and an illuminationcircuit connected to said pair of output power terminals and energizedon energization of said pair of output power terminals. 2. The inventiondefined in claim 1, wherein said pair of output power terminals isconstituted by an electrical convenience receptacle, and

including an electrical plug having connector prongs adapted to beinserted in said convenience receptacle, a voltage stepdown transformer,

said transformer being contained in a housing common to said electricalplug and having the primary winding thereof directly connected to theconnector prongs of said plug, and

a pair of low voltage terminals on the exterior of said housing, saidlow voltage terminals being directly connected to the secondary windingof said transformer whereby said low voltage terminals are energized onenergization of said pair of output power terminals for said selectedtime interval.

3. The invention defined in claim 2, including a low voltage controlsolenoid,

low voltage wiring means connecting said solenoid to said low voltageterminals,

means mounting said control solenoid in the proximity of a light controlmeans, and

means controlled by said control solenoid for actuating said lightcontrol means for said selected interval.

4. The invention defined in claim 3, wherein said means controlled bysaid control solenoid includes:

light control means actuating lever moved in one direction onenergization of said solenoid and returned to its initial position ondeenergization of said solenoid.

5. The invention defined in claim 1, including condition sensor meansconnected to said gate terminal of said electronic switch to supply agate signal thereto upon the sensing by same of an abnormal condition.

6. The invention defined in claim 1, including a tubular member foradmitting said radiant beam to said radiant beam sensor,

cap means'at the end of said tube remote from said sensor having anaperture therein of a size related to the length of said tube wherebythe included angle is between 6 and 13.

7. Lighting control apparatus comprising in combination,

an enclosure,

a tube projecting from said enclosure and extending inwardly of theexterior of said enclosure, the axis of said tube being angleddownwardly,

photocell means for detecting a light beam entering said tube at the endthereof exterior of said enclosure,

semiconductor switch means electrically connected to said photocellmeans and operated closed upon detection of said light beam by saiddetector,

time delay switch means energized on actuation of said semiconductorswitch means to electrically bypass said semiconductor switch means,

a pair of alternating current power output terminals, said alternatingcurrent power output terminals including a female outlet receptaclemounted in a wall of said enclosure,

means connecting the terminals of said electrical outlet receptacle toone side of a source of alternating current supply and to one side ofsaid time delay switch means, respectively, whereby said electricaloutlet receptacle is energized upon actuation of said time delay switchmeans, and

lighting means energized on energization of said electrical outletreceptacle.

8. The invention defined in claim 7, including a stepdown transformerand a housing for said transformer,

a pair of male prongs adapted to be plugged into said electrical outletreceptacle, said male prongs being connected in parallel with theprimary winding of said stepdown transformer and extending from thehousing of said transformer,

controlled means remote from said receptacle connected to the lowvoltage winding of said transformer and actuated on energization of saidelectrical outlet receptacle for controlling said lighting means.

9. The invention defined in claim 8, wherein said controlled meansincludes a solenoid,

means connecting the winding of said solenoid to receive the energizingcurrent from said low voltage winding of said transformer,

a lever arm actuated by said solenoid,

means mounting said lever arm on the actuating lever of a wall lightswitch, and

spring means biasing said lever in a direction to return said lightswitch to an off position on deenergization of said low voltagetransformer secondary.

10. Light actuated lighting system for buildings and the like having awindow, comprising in combination,

an electric lamp lighting system for said building for lighting theinterior thereof,

a photocell positioned in said building to be viewable from the exteriorthereof through said window,

an elongated tube means for limiting light reaching said photocell tolight directed thereto from a mobile artificial light beam sourcethrough said window and from the exterior of said building,

a triac connected in circuit with and a source of alternating currentpower,

means connecting said triac to said photocell to cause said triac toclose the circuit to said lighting system from said alternating currentelectric power supply upon a beam of light being directed to saidphotocell, and

time delay means connected in circuit with said triac and energizedthereby, switch means operated by said time delay means to bypass saidtriac and to carry load current to said lighting system for apredetermined time interval, and deenergize said lighting system aftersaid predetermined time interval and open the bypass of said triac.

11. A light beam controlled illumination apparatus comprising a pair ofelectrical power input terminals,

a pair of normally nonenergized electrical power output terminals lightbeam detector means,

first switch means actuated by said light beam detector means forconnecting said pair of input power terminals to said pair of outputelectrical power terminals to energize same,

time delay means electrically connected in parallel with said poweroutput terminals,

second switch means actuated by said time delay means a time intervalafter energization of said output terminals to deenergize said outputterminals, and

an illumination circuit connected to said pair of output power terminalsand energized from said output power terminals for said time interval12. The invention defined in claim 11, wherein said second switch meansincludes normally closed contacts connected in circuit between one ofsaid pair of input power terminals and one of said output powerterminals.

13. The invention defined in claim 11, wherein said light beam detectorincludes a cadmium sulfide cell the impedance of which varies as afunction of light, and

wherein said first switch means includes a relay having an operatingcoil, means connecting the operating coil of said relay in seriescircuit with said cadmium sulfide cell and said pair of input powerterminals said cell having an impedance when no light beam impingesthereon such that current flow through said relay coil is insufficientto operate same and an impedance when a light beam impinges thereuponwhich permits sufficient current to flow through said coil to energizesame,

a pair of normally open contacts, said pair of normally open contactsbeing closed by said relay coil on energization thereof,

first a conductor means connecting a first of 14. The invention definedin claim 13, wherein said second switch means includes normally closedcontacts connected in circuit between the other of said input powerterminals and said relay coil.

second conductor means connecting a second of said pair of normally opencontacts to one of said input power terminals and to one of said outputpower terminals to thereby energize said output power terminals onclosing of said second of said pair of normally open contacts.

1. Radiant beam controlled illumination apparatus comprising incombination, a pair of alternating current power input terminals, a pairof alternating current power output terminals, conductor means directlyconnecting one of said input power terminals to one of said output powerterminals, radiant beam controlled switch means for directlyelectrically connecting the other of said input power terminals to theother of said output power terminals for a selected time interval, saidradiant beam controlled switch means including an electronic switchhaving a pair of main terminals and a gate terminal, means connectingone of said main terminals to the said other of said input powerterminals and the other of its main terminals to the said other outputpower terminal, radiant beam sensor connected between said gate terminaland said the other of said input power terminals, said radiant beamsensor applying a signal to said gate terminal upon impingement thereonof a beam of radiant energy to render said electronic switch conductivebetween said main terminals, timer means, means connecting said timermeans across said pair of output power terminals, normally open switchmeans closed upon energization of said timer means for a selected timeinterval, means conneCting said normally open switch means in parallelto the said main terminals of said electronic switch to thereby bypasssaid electronic switch for said selected time interval, and anillumination circuit connected to said pair of output power terminalsand energized on energization of said pair of output power terminals. 2.The invention defined in claim 1, wherein said pair of output powerterminals is constituted by an electrical convenience receptacle, andincluding an electrical plug having connector prongs adapted to beinserted in said convenience receptacle, a voltage stepdown transformer,said transformer being contained in a housing common to said electricalplug and having the primary winding thereof directly connected to theconnector prongs of said plug, and a pair of low voltage terminals onthe exterior of said housing, said low voltage terminals being directlyconnected to the secondary winding of said transformer whereby said lowvoltage terminals are energized on energization of said pair of outputpower terminals for said selected time interval.
 3. The inventiondefined in claim 2, including a low voltage control solenoid, lowvoltage wiring means connecting said solenoid to said low voltageterminals, means mounting said control solenoid in the proximity of alight control means, and means controlled by said control solenoid foractuating said light control means for said selected interval.
 4. Theinvention defined in claim 3, wherein said means controlled by saidcontrol solenoid includes: light control means actuating lever moved inone direction on energization of said solenoid and returned to itsinitial position on deenergization of said solenoid.
 5. The inventiondefined in claim 1, including condition sensor means connected to saidgate terminal of said electronic switch to supply a gate signal theretoupon the sensing by same of an abnormal condition.
 6. The inventiondefined in claim 1, including a tubular member for admitting saidradiant beam to said radiant beam sensor, cap means at the end of saidtube remote from said sensor having an aperture therein of a sizerelated to the length of said tube whereby the included angle is between6* and 13*.
 7. Lighting control apparatus comprising in combination, anenclosure, a tube projecting from said enclosure and extending inwardlyof the exterior of said enclosure, the axis of said tube being angleddownwardly, photocell means for detecting a light beam entering saidtube at the end thereof exterior of said enclosure, semiconductor switchmeans electrically connected to said photocell means and operated closedupon detection of said light beam by said detector, time delay switchmeans energized on actuation of said semiconductor switch means toelectrically bypass said semiconductor switch means, a pair ofalternating current power output terminals, said alternating currentpower output terminals including a female outlet receptacle mounted in awall of said enclosure, means connecting the terminals of saidelectrical outlet receptacle to one side of a source of alternatingcurrent supply and to one side of said time delay switch means,respectively, whereby said electrical outlet receptacle is energizedupon actuation of said time delay switch means, and lighting meansenergized on energization of said electrical outlet receptacle.
 8. Theinvention defined in claim 7, including a stepdown transformer and ahousing for said transformer, a pair of male prongs adapted to beplugged into said electrical outlet receptacle, said male prongs beingconnected in parallel with the primary winding of said stepdowntransformer and extending from the housing of said transformer,controlled means remote from said receptacle connected to the lowvoltage winding of said transformer and actuated on energization of saidelectrical outlet receptacle for controlling said lightiNg means.
 9. Theinvention defined in claim 8, wherein said controlled means includes asolenoid, means connecting the winding of said solenoid to receive theenergizing current from said low voltage winding of said transformer, alever arm actuated by said solenoid, means mounting said lever arm onthe actuating lever of a wall light switch, and spring means biasingsaid lever in a direction to return said light switch to an off positionon deenergization of said low voltage transformer secondary.
 10. Lightactuated lighting system for buildings and the like having a window,comprising in combination, an electric lamp lighting system for saidbuilding for lighting the interior thereof, a photocell positioned insaid building to be viewable from the exterior thereof through saidwindow, an elongated tube means for limiting light reaching saidphotocell to light directed thereto from a mobile artificial light beamsource through said window and from the exterior of said building, atriac connected in circuit with and a source of alternating currentpower, means connecting said triac to said photocell to cause said triacto close the circuit to said lighting system from said alternatingcurrent electric power supply upon a beam of light being directed tosaid photocell, and time delay means connected in circuit with saidtriac and energized thereby, switch means operated by said time delaymeans to bypass said triac and to carry load current to said lightingsystem for a predetermined time interval, and deenergize said lightingsystem after said predetermined time interval and open the bypass ofsaid triac.
 11. A light beam controlled illumination apparatuscomprising a pair of electrical power input terminals, a pair ofnormally nonenergized electrical power output terminals light beamdetector means, first switch means actuated by said light beam detectormeans for connecting said pair of input power terminals to said pair ofoutput electrical power terminals to energize same, time delay meanselectrically connected in parallel with said power output terminals,second switch means actuated by said time delay means a time intervalafter energization of said output terminals to deenergize said outputterminals, and an illumination circuit connected to said pair of outputpower terminals and energized from said output power terminals for saidtime interval
 12. The invention defined in claim 11, wherein said secondswitch means includes normally closed contacts connected in circuitbetween one of said pair of input power terminals and one of said outputpower terminals.
 13. The invention defined in claim 11, wherein saidlight beam detector includes a cadmium sulfide cell the impedance ofwhich varies as a function of light, and wherein said first switch meansincludes a relay having an operating coil, means connecting theoperating coil of said relay in series circuit with said cadmium sulfidecell and said pair of input power terminals said cell having animpedance when no light beam impinges thereon such that current flowthrough said relay coil is insufficient to operate same and an impedancewhen a light beam impinges thereupon which permits sufficient current toflow through said coil to energize same, a pair of normally opencontacts, said pair of normally open contacts being closed by said relaycoil on energization thereof, first a conductor means connecting a firstof
 14. The invention defined in claim 13, wherein said second switchmeans includes normally closed contacts connected in circuit between theother of said input power terminals and said relay coil. secondconductor means connecting a second of said pair of normally opencontacts to one of said input power terminals and to one of said outputpower terminals to thereby energize said output power terminals onclosing of said second of said pair of normally open contacts.